High velocity pneumatic device

Abstract

A high velocity pneumatic device having particular use for excavating or dislodging soil. The device includes a body or housing having a passage that connects a source of air under pressure, such as a compressor, to an elongated discharge tube. A valve mechanism is disposed in the passage and controls the flow of air through the tube. Mounted in the distal end of the tube is a nozzle having an inwardly converging upstream and an outwardly diverging downstream end which increases the velocity of the air being discharged through the tube. A manually operable trigger is directly connected to the valve mechanism and actuates the valve to discharge air through the tube. The nozzle is formed of a non-sparking metal, such as brass, while the tube is composed of an electrically nonconductive material, such as glass reinforced resin.

We claim: 
     
       1. A high velocity pneumatic excavating apparatus, comprising a body having passage means extending therethrough, gas supply means connected to said passage means for supplying a gas under pressure to said passage means, an elongated tube having one end connected to said passage means and having a distal end, valve means disposed in said passage means for opening and closing said passage means, a separate nozzle mounted on the distal end of said tube and constructed and arranged to increase the velocity of the gas being discharged through said nozzle, manual actuating means operably connected to said valve means for moving said valve means to an open position to enable gas to pass through said passage means to said tube, said nozzle being composed of a nonsparking metal and said tube being electrically non-conductive and composed of fiber reinforced thermosetting resin. 
     
     
       2. The apparatus of claim 1, wherein said non-sparking metal is brass. 
     
     
       3. The apparatus of claim 1, wherein said actuating means comprises a trigger pivoted to said body, one end of said trigger defining a hand grip to be engaged by an operator and a second end of said trigger being operably connected to said valve means. 
     
     
       4. The apparatus of claim 3, wherein the hand grip is aligned with said tube. 
     
     
       5. The apparatus of claim 1, and including deflector means mounted on the tube and having a generally conical distal end disposed radially outward of the distal end of said tube. 
     
     
       6. The apparatus of claim 5, wherein said deflector means has a small diameter end secured to the outer surface of said tube and a larger diameter distal end. 
     
     
       7. The apparatus of claim 6, and including adjusting means for adjusting the position of said deflector means on said tube. 
     
     
       8. The apparatus of claim 1, wherein said nozzle defines an orifice with the upstream end of said orifice converging inwardly and the downstream end of said orifice diverging outwardly. 
     
     
       9. The apparatus of claim 1 and including pressure indicating means disposed on said body for indicating the pressure of said gas. 
     
     
       10. The apparatus of claim 1, wherein said nozzle is annular in shape and an end of said nozzle has an outwardly extending radial flange, the distal end of said tube being engaged with said flange. 
     
     
       11. A high velocity pneumatic excavating apparatus, comprising a body having passage means extending therethrough, gas supply means connected to said passage means for supplying a gas under pressure to said passage means, a tube having one end connected to said passage means and having a distal end, valve means disposed in said passage means for opening and closing said passage means, a nozzle mounted in the distal end of said tube and constructed and arranged to increase the velocity of the gas being discharged through said nozzle and against a material to be excavated, manual actuating means operably connected to said valve means for moving said valve means to an open position to enable gas to pass through said passage means to said tube, a sleeve spaced outwardly of said tube to provide an annular chamber therebetween, port means in said tube providing communication between the interior of said tube and said chamber, and discharge means communicating with said chamber for discharging gas from the chamber and around the tube in the form of an annular curtain, wherein said sleeve has an operative position where said port means communicates with said chamber and an inoperative position where a portion of said sleeve closes off said port means so that said port means is out of communication with said chamber. 
     
     
       12. The apparatus of claim 11, wherein said portion comprises an annular section on the inner surface of said sleeve. 
     
     
       13. The apparatus of claim 11, wherein said discharge means comprises a plurality of circularly-spaced ports. 
     
     
       14. The apparatus of claim 13, wherein said ports are disposed at an acute angle to the axis of said tube. 
     
     
       15. The apparatus of claim 11, and including sealing means for sealing the ends of said sleeve to said tube. 
     
     
       16. The apparatus of claim 11, wherein said sleeve is slidable longitudinally on said tube. 
     
     
       17. The apparatus of claim 16, and including locking means for locking the sleeve in position relative to said tube. 
     
     
       18. The apparatus of claim 14, wherein said ports are disposed at an angle of 30° to 60° degrees with respect to the axis of said tube. 
     
     
       19. A high velocity pneumatic apparatus, comprising a body having passage means extending therethrough, gas supply means connected to said passage means for supplying gas under pressure to said passage means, a tube having one end connected to said passage means and having a distal end, valve means disposed in said passage means for opening and closing said passage means, a nozzle mounted in the distal end of said tube and constructed and arranged to increase the velocity of the gas being discharged through said nozzle, actuating means operably connected to said valve means for moving said valve means to an open position to enable gas to pass through said passage means to said tube, said nozzle having an upstream end and a downstream end and having an orifice extending between said ends, said orifice including an upstream inwardly converging section and a downstream outwardly diverging section terminating in an outlet, said downstream end being disposed normal to the axis of said orifice, end having a recess coaxial with said orifice, and said recess having a greater diameter than said outlet. 
     
     
       20. The apparatus of claim 19, wherein said recess includes a bottom wall disposed parallel to said downstream end and an annular side wall connecting said bottom wall to said downstream end. 
     
     
       21. The apparatus of claim 20, wherein said side wall is disposed at an angle to the axis of said orifice and diverges outwardly from said bottom wall.